1. Field of Invention
The present invention relates to a flatbed trailers and box-type truck structures (e.g., vans, container chassis, etc.) and, in particular, the invention pertains to an improved attachment of suspension hangers to aluminum flatbed frames.
2. Description of Related Art
The main bearing members for loads placed on flatbed trailers are a pair of I-beams, generally known as the “main beams” which run longitudinally the length of the bed. Properly fabricated, the beams are flexed or curved vertically upward and designed to compress or straighten longitudinally under load. Coupling of the wheel axles to the main beams is typically achieved via “suspension hangers” on each side of the flatbed which are connected together by a cross member.
Where these main beams are steel, the lower flange portion of the main beams can be welded to the suspension hangers. However, where the main beams comprise aluminum, the lower flanges thereof cannot be welded to the suspension hangers; instead, they are bolted to the suspension hangers through the lower flange portions, as shown in FIG. 1. In particular, a support plate 2 is welded to its corresponding suspension hanger 4. A cross beam 6 is welded to the suspension hangers at each end. The lower flange portion 7 of each aluminum main beam 8 is then bolted 10 to the support plate 2. The problem, though, with bolting the suspension hangers 4 through the lower flange portions 7 is that holes are created in the highly-stressed lower flange portions 7. This weakens and adds stress to the lower flange portion 7 which can cause premature failure in this area.
The following U.S. patents are related to the field of flatbeds or trucks, including their respective main beam/suspension assemblies: U.S. Pat. No. 1,962,497 (Francis); U.S. Pat. No. 3,197,228 (Felburn); U.S. Pat. No. 4,166,640 (Van Denberg); U.S. Pat. No. 4,534,589 (Booher); U.S. Pat. No. 4,789,181 (Baxter); U.S. Pat. No. 4,906,021 (Rowe, et al.); U.S. Pat. No. 5,085,025 (Gaddis); U.S. Pat. No. 5,205,587 (Orr); U.S. Pat. No. 5,366,237 (Dilling, et al.); U.S. Pat. No. 5,558,369 (Cornea, et al.); U.S. Pat. No. 5,649,719 (Wallace, et al.); U.S. Pat. No. 5,845,919 (VanDenberg); U.S. Pat. No. 6,916,037 (Baxter, et al.); and U.S. Pat. No. 7,350,795 (Svartz, et al.).
Thus, there remains a need for a device and method for securing the suspension hangers to the aluminum main beams without penetrating the lower flange portions of the main beams.
All references cited herein are incorporated herein by reference in their entireties.